Speak to your doctor before starting new exercises. Your doctor may recommend other exercises and additional stretches. Physical therapists can also tailor an exercise regime for your particular condition.
Start all new exercises slowly at first. Expect to feel some fatigue in the muscles you are working, but you do not want to feel pain in the affected joint. Listen to your body. It will tell you if you are doing too much or if an exercise is inappropriate for you. The goal is to work the muscles, but be pain free while doing the exercises.
If you see swelling or are in persistent pain, immediately stop the exercises and consult your doctor.
Walking is one of the best exercises. It does not require any special skills, equipment and can be done anywhere at your leisure. Make your walks interesting by picking different routes or bringing along a friend. And it soothes the mind too.